02-08-2010 11:21 AM
I would appreciate some help identifying the units associated with the unscaled output from a NI 9237 Analog Input Module?
The module is being used with a full bridge load cell and a bridge supply of 2.5 V. When I set up the load cell with a stable power supply and measure the output with a voltmeter I get ~0.1 mV of a change for the applied load but when the same setup and load is used with a NI9237 in a cRIO the numerical output changes by only ~0.05. I initially assumed that the 0.05 was in mV but this does not now seem to be correct.
Best regards,
nos
02-10-2010 06:33 AM
There is an entry in the knowledge base that explains that the NI 9237 returns values in volts per volt of excitation rather than just volts, see http://digital.ni.com/public.nsf/allkb/21CA039D8F43C5188625729F005AC2F7 , I obtained this from NI technical support.
It seems to me however that this piece of information should be displayed to the user far more prominently than it currently is, the only other reference to it that I have found is under Analog Input Modules in Help.
nos